<!DOCTYPE html>
<html>
<head>
    <meta charset='UTF-8'>
    <title>显示</title>
    <style>
        h1.hidden {
            visibility: hidden;
        }
        h1.none {
            display: none;
        }
    </style>
</head>
<body>
    <h1>This is a visible heading</h1>
    <h1 class="hidden">This is a hidden heading</h1>
    <h1>然而上边的visibility为hidden的h1依旧占着空间</h1>
    <hr>
    <h1>This is a dispaly: block heading</h1>
    <h1 class="none">This is a display: none heading</h1>
    <h1>display: none的h1不再占据空间</h1>
</body>